This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Computation is an essential component of image guided therapy research. Preoperatively, we use segmentation, registration, and visualization technology to prepare patient-specific anatomical models. At our site, most such capabilities are available in 3D Sheer, an open-source platform that was developed for IGT applications. During image-guided interventions, it can be important to control scan, and even pulse sequence parameters on the fly. Once image data has been acquired, it is very useful to register the intra-operative images with pre-operative images, so that treatment plans can be transferred into the space of the patient. Furthermore, such intra-operative computations should be carried out in a timely way. Finally, IGT projects frequently require the coordination of diverse equipment. It has proven difficult for application projects to meet these needs in a systematic way. The Computational Core contains three specific aims that were designed to enhance our capabilities in all of the area described above. Slicer Engineering focuses on the development of important Slicer capabilities that are specific to IGT. Interactive and Adaptive Platforms will develop modules for on-line control of MRI parameters and pulse sequences, and finally, High Performance Computing (HPC) will facilitate our use of advanced image processing algorithms, both pre-operatively, and intraoperatively, while observing realistic time constraints.